1. Field of the Invention
The present invention relates in general to a method of forming a carbon nano-material layer, and more particularly, to a method of forming a carbon nano-material layer using a cyclic deposition technique.
2. Description of Related Art
Carbon may have four types of crystal structures such as diamond, graphite, fullerene, and carbon nanotube (CNT). Fullerene and CNT may be considered as carbon nano-materials. Fullerene may be composed of sixty carbon atoms and may be a 64-hedron with a soccer ball shape. CNT may be formed into hexagonal honeycomb structures wound into a tube shape, in which there are several types of shapes such as a single wall shape, a multi-wall shape, and a rope shape, for example.
CNT may have the property of an electric conductor or a semiconductor due to the wound shape, and may have excellent mechanical, electrical and chemical characteristics. For these reasons, CNT may be a suitable material for use in highly-integrated memory devices, ultra high capacity capacitors, secondary batteries, high sensitivity sensors, high strength-ultra light complex materials, electromagnetic waves-shielding materials, field emission displays (FEDs), and the like.
CNT may have been first introduced in NATURE (Vol. 354, pp. 56-58, 7 Nov. 1991) in a research paper by Sumio Iijima entitled “HELICAL MICROTUBULES OF GRAPHITIC CARBON”. The research paper indicates that materials including CNT may be produced by an arc discharge between two graphites. Subsequently, methods of forming a carbon nano-material, such as a laser ablation, electrochemical method, chemical vapor deposition (CVD) method and plasma enhanced CVD method, have been introduced. However, the above methods are not without shortcomings. For example, conventional forming techniques may tend to involve relatively high substrate temperatures, generate carbon particles by gas phase reaction, and/or suffer from carbon particles interfering with the formation of a carbon nano-material layer having a desired shape and property.
In electronic devices such as a highly-integrated semiconductor device, and when forming such a carbon nano-material layer on the highly-integrated semiconductor device, a need may exist for a method of forming a carbon nano-material layer at relatively low temperatures, and for preventing the generation of carbon particles that may interfere with the formation of a carbon nano-material layer with desired shapes and properties.